Consider the following statements in respect of worm gears:
1. They are used for very high speed reductions.
2. The velocity ratio does not depend on the helix angle of the worm.
3. The axes of worm and gear are generally perpendicular and nonintersecting.
Which of the statements given above are correct?
Option (A)
1 and 2
Option (B)
1 and 3
2 and 3
1, 2 and 3
Correct Option:
Question Solution:
Velocity ratio = (In one revolution of worm / Angle turned by worm in one revolution of worm)
(q2/q1) = {2(L/dn) / 2p} = (L / pd2)
V.R. = (nPa / pd2) which is independent on helix angle